Chisel retainer for riveting hammers



Jan. 4, 1927. ,613,399

A. LEVEDAHL CHISEL RETAINER FOR RIVETING HAMMERS Filed F'eb. l0. 1922 raceteam. 4,1927.

UNITED STATES" PATE-NT oFFicE.

AXEL LEVEDAHL, F AURORA, ILLINOIS, ASSIGNOR TO INDEPENDENT IPNEUMIATICl TOOL COMPANY, OF CHICAGO, `ILLINOIS, A CORPORATION 0F DELAWARE. l

CHISEL RETAINER FOR RIVETING HAMMERS.

- Application led February 10, 1922. Serial No..535,624.

.This invention relates to chisel retainers for pneumatic tools and more particularly for riveting hammers so that chisels may be applied to the latter for cutting oil'. rivet heads in the removal of rivets in repair and other work.

One object of my invention is to provide a retainer permitting limited longitudinal movement of the chisel with respect to the sleeve in which the chisel is inserted so that the blows of the hammer piston on the chisel will have their full effect in the cutting operation of the tooltand will not be fully absorbed in the parts of the retainer or the bar` rel of the tool to impairthe cutting operation. of the latter as heretofore.

Another object is to provide a retainer which will hold a relatively light chisel and thus permit the ordinary type of pneumatic riveting hammer being eiiiciently employed for-cutting o3 the heads of rivets. y

A further object of my invention is to retard or break the outward movement of the chisel at a point in such movement, not only to hold the chisel from dro ping out of the barrel of the tool when the atter is idle,.but to preventthe chisel and its holding sleeve from being shot out of the barrel by the vhammer piston, either when the tool is operated before the chisel is placed against the work or when the chisel glances oil a rivet while being cut and when the rivet head breaks od'.

The invention consists further in the matters hereinafter described and more particularly set forth in the appended claims.

In the accompanying drawingsliig. l is a side elevational view of a pneu matic riveting-hammer having attached to the forward end of the barrel thereof a chisel retainer of' my invention;

Fig. 2 is anenlarged fragmentary longitudinal vertical sectional view through the forward end of the barrel and attached chisel retainer;

Fig. 3 is a transverse vertical sectional view taken on line 3-3 of Fig. 2,

Fig. 4 is an elevational view of one of the plugs used in the retainer structure, and

Fig. 5 is a transverse sectional view on line 5-5 oit Fig. 2; and

Figli is an end View of the barrel, the retainer being omitted for thevsake of illustration.

In the drawings, 1 indicates the barrel of a pneumatic'riveting hammer/of the type handled by one man in setting rivets'in steel structures. Attached to the forward end of said barrel Ais a chisel retainer of my invention, so that a chisel 2 may be applied to said riveting hammer and .permit use of the latter for cutting ofi" the heads of rivets in repair or other work.

Surrounding the forward end of said barlrel l is a retainer sleeve 3 made in one piece and held on the barrel by two dogs 4, 4, preferably diametricallyopposed and fastened as by rivets a, a toa spring clip 5 on the outside of said sleeve 3. Said dogs 4, 4 have inwardly extending prongs 6, 6 which extend into grooves 7 in the barrel 1 through slots 3a, 3a in the sleeve 3, 'as shown in Figs. 2 and 5. The inner ends of the prongs 6, 6 are rounded and the grooves 7, 7 are made concave on the same curvature, so that by turning the' sleeve 3, the prongs will ride out of the grooves 7 on to the outer surface of the barrel between the grooves, whereupon the sleeve 3 and its spring clip 5 and rongs 6 as a complete assembly may be pul ed od' over the end of the barrel. The spring clip 5, which was expanded by the prongs rid-l ing out of the grooves, contracts against the sleeve 3 and holds the `prongs projecting into the same, when the sleeve is ed' lthe barrel. rlhe end of the barrel is milled on o posite sides, preferably mid-way between the grooves 7 to provide dat inclined surfaces 8,

8, as shown in Fig. 6. In replacing the sleeve 3 on the barrel, the sleeve is first positioned with the prongs 6 of the dogs at the inclines 8 and is then pushed inward over the barrel until the prongs 6 come into the planes of the grooves, whereupon the sleeve is turned to carry the prongs to the grooves, the expanded'spring clip 5 snapping the prongs into the grooves to fasten the sleeve 3 on the barrel, as is apparent.

As shown in Fig. 2, the sleeve 3 extends l forward beyond the end of the vbarrel l to provide a space between such parts.. ln` serted in the forward end of the barrel is a metal sleeve 9 preferably made of steel and tittingthe end or nozzle of the barrel,.- This sleeve `9 pro'ectsinto the space between the end of the arrel and the forward e'nd of the sleeve 3, which there is provided with an inwardly extending flange 10, as shown in Fig. 2. Said sleeve 9 is provided beyond the end of the barrel 1 with an outwardly extending annular ,flange 11, and between the saine and the flange 10 of the sleeve Sis cushion means 12, such as soft flexible ma l to the longitudinal axis of the chisel. Said grooves 14, 14 are made concave or rounded in cross-section and have a length less than that of the sleeve 9, as shown in Fig. 2. Into these. grooves-14, 14 extend plugs 15, 15 carried by the sleeve 9 and having their inner ends rounded to conform to the shape of the grooves 14. Said plugs 15, t in holes or. recesses in the sleeve 9, as shown. The outer ends of the plugs 15 are rounded olf on a radius equal approximately to the bore of the nozzle 1 and engage the same. The plugs being thus'made are slightly below the surfacef'of the sleeve on opposite I sides, as indicated at 16, 16, in Fig. 2. This metal is set over slightly and prevents the plugs from dropping out of the holes in the sleeve 9.

In assembling the parts, the ,chisel shank 13 is lirst inserted into the sleeve 9 .while both of such parts are outside of the barrel 1 and the metal of the sleeve set over to hold the plugs in place, as described. Then the assembled parts are inserted into the barrel 1 and the retainer sleeve 3 applied with the packing 12 in place, as shown.

The inner end of the chisel shank 13 extending beyond the` inner end 'of the sleeve 9 receives the blows ofthe hammer piston in the operation of the tool and drives the chisel forward with force 'against the work. The grooves 14, 14 permita limited longitudinal movement of the chisel shank 13 in the sleeve 9 and thus allows the blows on the chisel to have full eect in the cutting operation without being absorbed by either the barrel`1 or the sleeve 9 to impair the force of these blows. The grooves 14, 14 have their` ends inclined outward, as shown, and when these ends approach the plugs 15 as the chisel is driven forward, the plugs exert a wedging effect on the chisel shank to retard its outward movement. The plugs l bearing against the bore of the barrel 1 are heldv from movement out of the grooves 14,

out of the sleeve 9. When this wedgiiig' action takes place, the sleeve 9 is also moved outward with the chisel shank, and by the flanges 10 and 11 on the sleeves 3 and 9 and the interposed cushion means 12, the outward movement of the parts is retarded and shooting of the sleeve 9.out of the barrel is prevented. Thus, the parts cannot be shot out of the barrel, either when the tool is operated while removed from'the work or when the chisel glances off of the work during the operation of the tool and when the rivet head breaks oli'. This provides a safety feature and lallows the operator to cut off heads of rivets without fear ofthe. chisel being shot out ofthe barrel when the chisel glances i 'off andwhen the rivet head is cut oli'. This saves time for`the operator and enables more work to be done in a given space of time, as he does not have to be concerned with keeping the chisel in the barrel.

The plugs 15 having their outer ends curved, as stated, permit turning the chisel on its axis to comply with the surface of the work, as the sleeve 9'will turn freely in the tool nozzle except when its endwise movement is checked. f

Moreover, by the construction described, an ordinary pneumatic riveting hammer as handled by one man may be used' with a' comparatively light chisel for cutting olf the heads of rivets. Such riveting hammer with its quick stroke and automatic hammer piston has suicientpower for this work when a comparatively light chisel is einployed as not enough of the blow of the hammer piston is transferred to the barrel -of the tool' to make the tool when put to 4 this use, ineiicient,was heretofore with a comparatively heavy chisel tted in the barrel of the hammer. a

While I have'shown and described herein in detail a. chisel retainer of my invention, it is of course to be understood thatl the details of construction and arrangement of parts illustrated may be variously changed ilol and modified without departing from the 1 spirit and scope of my invention.

`I claim as my invention: Q l. The combination with the barrel of a percussive tool, of a chisel having its shank Su ported in said barrel for relative longituinal movements, and means associated with the barrel for retaining the chisel shank nroperating position in the barrel comprisfor initially .braking the outwar sai ing means longitudinal movement of 'the shank, latter means comprising a. sleeve disposed intermediate the barrel and shank, a braking 1f element carried by the sleeve and engageable with the barrel and shank, and a cushion for receiving the impact of said sleeve subsetjuent to the initial retardation of the outsaid inner sleeve for connecting said shank' and sleeve whereby they will continue outward longitudinal movement in unison, said, connecting means cooperating with'the barrelto gradually retard further outward movement of .the`slceve and shank, and a cushion interposed between said sleeve; to.

receive the impact ofthe inner sleeve subsequent to the initial retardation of the outward movement of said shank.

- 3. The combination with the barrel of a percussive tool, of a chisel having its shank inserted in said barrel, and a retainer carried by the barrel for supporting and retaining the shank therein for relative longitudinal movements, said retainer including braking and cushion elements acting in the order :namedto (prevent the shank from being shot out'of sai barrel by the piston therein, said braking elements, being interposed between the shank and the barrel and being forced j into frictional engagement with the bore of the barrel by' the shank in the outward movement of the shank 'to retard the same.

et. The 'combination with the barrel of a percussivetoohiof a chisel having its shank inserted insaid'barrel, and al retainer carried bysaid barrel for supporting and retaining theshank thereinfor limited longitudinal, movements, said retainer including braking andfcushionv elements acting in thev order named to revent the shank from being shot out o the barrel by the piston therein, said braking elements being interposed between/the shank and the barrel, and

. inclined 1 means onthe` shank to force the g--rfg'lfhe combination with-the barrel of a i percussive tool, of a sleeve slidably mounted in said barrel, a chisel having a shank inserted in saldsleeve and projecting beyond the inner end thereof, braking elements rel tained by said sleeve between the shank and )the barrel and -engagin yboth of the same, inclined means `on the s ankfor forcing the braking elements into'frictional engagement with the bore of the barrel .in the outward movement 0f the shank to retard the same, and means to check the outward movement of the sleeve' with said shank.

`6. The combination with the barrel`of a percussive tool, of a chisel retainer, .coinprising a sleeve inserted inthe forward end of said barrel, a chiselhaving a shank inserted in said sleeve and projecting beyond the inner end thereof, said'shank being provided with longitudinal grooves havin inclined ends, plugs carried by said seevev ani engaging in said'grooves, said plugs being held against movement outl of said grooves by said barrel, and means associated with said barrel for holding said sleeve therein.

7. The combination with the barrel of a percussive tool, of a chisel retainer, comprising a sleeve inserted in the forward end of said barrel, a chisel, having a shank inserted in said sleeve and projecting beyond` the inner end thereof, said shank being provided with longitudinal concave grooves with inclined ends, plugs carried by said sleeve and having rounded inner ends litting in said grooves, said plugs being held against movement out of said grooves by said barrel, a retainer sleeve applied about the forward end of Said barrel and projecting beyond the same, means for holding said retainer sleeve on said barrel, and means for holding said chisel sleeve in said barrel, consisting of flanges on said sleeves and cushionmeans between said fianges and carried by lone of said sleeves.

8. The combination with the barrel of a percussive tool, of a chisel retainer, comprising a sleeve inserted Vin the forward endof the barrel and having a plurality of transverse holes therein, a chisel having a shank inserted-in said sleeve and projecting beyoud the inner end thereof, said shank having a plurality of longitudinal concave grooves with inclined ends, plugs in said `holes and having rounded inner ends litting in said grooves,.th outer ends of said plugs engagingthe non-yielding portion of the barrel surrounding said sleeve, a retainer sleeve applied about the forward end of said barrel and projecting beyond the same, and means for holding said chisel sleeve in said bauch-consisting of ianges on said sleeves and acushion means between said anges and carried by one of said sleeves. l 9. Thev combination with the barrel of prlslng a sleeve insefrted in the forward end of the barrel and having aplurality of transverse holes therein, a chisel having a shank inserted in said sleeve and projecting beyond the inner end thereof,said shank having a plurality of longitudinal concave grooves with inc ined ends, plugs in said holes and-having rounded inner ends .fitting in said grooves, the outer ends of said'plugs MIU a percussivel tool, of a chisel retainer, comengaging the non-yielding portion of the said 'anges and carried by one of said barrel surrounding said sleeve and being sleeves. I l l t curvedy on a radius approximating that of In testimony that I claim the foregoing 10 the bore of said barrel, a retainer sleeve as my invention, I aix my signature this applied about the forward end of said bar? Ith day of February, A. D. 1922.

rel and projecting beyond the same, angs on said sleeves, and cushion means between Y AXEL LEVEDAHL. 

